[V8] Starter Bolt?

[Tom Laplante]

20mm would be .78" and I just checked and I cut mine more like  
30(1-1/4") and mine is maybe a bit long, but have used it 3-4  
times....and it was buried in the bottom of a messy toolbox, as it's  
only got 1 use in this world...I also use a ratcheting box end and a  
short(8") piece of pipe to break it loose.  The duct tape helps keep  
the allen in place.  If you put antisieze/corrosionx on the bolt when  
you reinstall, it's a joy to remove the next time....Tom

http://tinyurl.com/bulho8e